Initial commit: notification-elements-demo app

Interactive Angular 19 demo for @sda/notification-elements-ui with
6 sections: Bell & Feed, Notification Center, Inbox, Comments &
Threads, Mention Input, and Full-Featured layout. Includes mock
data, dark mode toggle, and real-time event log.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

node_modules/needle/examples/download-to-file.js

@@ -0,0 +1,18 @@
+var fs = require('fs'),
+    needle = require('./..'),
+    path = require('path');
+
+var url  = process.argv[2] || 'https://upload.wikimedia.org/wikipedia/commons/a/af/Tux.png';
+var file = path.basename(url);
+
+console.log('Downloading ' + file);
+
+needle.get(url, { output: file, follow: 3 }, function(err, resp, data){
+  console.log('File saved: ' + process.cwd() + '/' + file);
+
+  var size = fs.statSync(file).size;
+  if (size == resp.bytes)
+    console.log(resp.bytes + ' bytes written to file.');
+  else
+    throw new Error('File size mismatch: ' + size + ' != ' + resp.bytes);
+});